The development of various voice over IP protocols such as the H.323 Recommendation and the Session Initiation Protocol (SIP) has led to increased interest in multimedia conferencing. In such conferencing, typically, a more or less central server or other device manages the conference and maintains the various communications paths to computers or other client devices being used by parties to participate in the conference. Parties to the conference may be able to communicate via voice and/or video through the server and their client devices.
Instant messaging can provide an added dimension to multimedia conferences. In addition to allowing text chatting, instant messaging systems such as the Microsoft Windows Messenger™ system can allow for transfer of files, document sharing and collaboration, collaborative whiteboarding, and even voice and video. A complete multimedia conference can involve multiple voice and video streams, the transfer of many files, and much marking-up of documents and white boarding.
Participants in the multimedia conference or collaboration effort as well as other users may want to provide a voice, text, graphical, or other type of annotation regarding a document used in the conference or collaboration, their thoughts regarding the conference or collaboration effort, etc. The annotation may be provided back to other participants in the conference or collaboration effort for further review. As such, there is a need for a system and method for allowing multiple annotations to co-exist while distinguishing between the annotations made by different participants or other users.